This is why it is extremely important that you get 8-9 hours of quality sleep every single night. Adolescence is the very period when appearance plays a very important role. A good approach to a hair loss problem would be a visit to a dermatologist.
It is a member of the testosterone potato family and is known for its energizing and balancing effect on the body. They interpret things such as your posture as hints to the type of man you are. My advice is that if they are a problem; pay special attention to working the hamstrings in your training program. Are you a hardgainer who feels that it is impossible to build muscle mass?